<!DOCTYPE html>
<title>ok</title>
<script>
window.onmessage = function(e) {
    var id = e.data.id;
    try {
        self.caches;
        window.parent.postMessage({id: id, result: 'allowed'}, '*');
    } catch (e) {
        window.parent.postMessage({id: id, result: 'denied', name: e.name, message: e.message}, '*');
    }
};
</script>
